An eyeglass frame shape measuring apparatus includes an eyeglass frame holding unit which holds an eyeglass frame, and a measuring unit which moves a tracing stylus inserted into a rim of the held eyeglass frame along a contour of the rim (refer to JP-A-2011-122898, JP-A-2000-304530 and JP-A-2000-314617). The eyeglass frame shape measuring apparatus includes a moving mechanism which moves the measuring unit to each of measurement positions of a right rim and a left rim in order to measure the right rim and the left rim held by the eyeglass frame holding unit. The eyeglass frame holding unit includes two sliders which are movable to be open and closed in order to hold the right rim and the left rim of the eyeglass frame by interposing the rims therebetween in a longitudinal direction (upper-lower direction of eyeglasses when worn).
However, in a related-art eyeglass frame shape measuring apparatus, a main mechanism of the measuring unit is disposed on a front side (a side opposite to an eye side of a wearer) of the eyeglass frame held by the eyeglass frame holding unit. In such a configuration, it is difficult to measure a high-curve frame.
In the apparatus of JP-A-2011-122898, in order to measure a high-curve frame, a tip of the tracing stylus is configured to be tiltable on a rear side of the eyeglass frame. However, since the measuring unit is disposed on a front side of the eyeglass frame, the apparatus employs a mechanism which causes a holding mechanism of a tracing stylus shaft to largely move outward further than a contour of the rim, so that a size of the mechanism of the measuring unit would increase.
In the apparatus of JP-A-2000-304530, since the measuring unit is disposed on the front side of the eyeglass frame, the tip of the tracing stylus is configured to tilt on the front side of the eyeglass frame. Therefore, there would be a problem in that the tip of the tracing stylus does not precisely come into contact with a rim groove when measuring the high-curve frame, and there would be another problem in that the tracing stylus easily deviates from the rim groove. That is, this apparatus cannot support measurement of the high-curve frame.
In the apparatus of JP-A-2000-314617, a tracing stylus shaft and a tilt angle of the tip of the tracing stylus are fixed, and therefore, there would be a problem in that the tracing stylus does not precisely come into contact with the rim groove when measuring the high-curve frame, and there would be another problem in that the tracing stylus easily deviates from the rim groove.
Further, in a related-art eyeglass frame holding unit, guide mechanisms which move two sliders to be open and closed are disposed at both right and left ends of the sliders, respectively. Since an operator holds the right and left temples of the eyeglass frame with one's hands, it is difficult to set the frame between two sliders in the related-art apparatus. Particularly, in a configuration where the eyeglass frame is disposed in a substantially horizontal direction, or in a configuration where a measuring mechanism is provided on a rear side (an eye side of a wearer) of the eyeglass frame, it would be more difficult for the operator to set the eyeglass frame. Further, the related-art apparatus requires a large space in a left-right direction, so that a size of the apparatus would increase.